Evaluation of peripheral and central venous pressure in awake dogs and cats

Objective - To determine whether peripheral venous pressure (PVP) was correlated with central venous pressure (CVP) when measured by use of different catheter sizes, catheterization sites, and body positions in awake dogs and cats. Animals - 36 dogs and 10 cats. Procedures - Dogs and cats with functional jugular and peripheral venous catheters were enrolled in the study. Peripheral venous catheters (18 to 24 gauge) were placed in a cephalic, lateral saphenous, or medial saphenous vein. Central venous catheters (5.5 to 8.5 F) were placed in the jugular vein and advanced into the cranial vena cava. Catheters were connected to pressure transducers and a blood pressure monitor capable of displaying 2 simultaneous pressure tracings. For each animal, the mean of 5 paired measurements of PVP and CVP was calculated. The relationship between PVP and CVP when measured by use of different catheter sizes, catheterization sites, and body positions was determined. Results - Mean ± SD PVP was 5.7 ± 5.8 mm Hg higher than CVP in dogs and 6.0 ± 6.9 mm Hg higher than CVP in cats. However, results of multiple regression analysis did not indicate a significant correlation between PVP and CVP regardless of catheter size, catheter position, or body position. The relationship was weak in both dogs and cats. Conclusions and Clinical Relevance - The PVP was poorly correlated with CVP when different catheter sizes, catheterization sites, and patient positions were evaluated. Peripheral venous pressure should not be used to approximate CVP in awake dogs and cats.